public enum EnumSingleton1 {
    /**
     * 单实例
     */
    INSTANCE {
        @Override
        public void printTest() {
            System.out.println("INSTANCE...print..." + testname);
        }

        public String testname;
    };
    public String testname;
    public abstract void printTest();

    public void doSomething() {
        System.out.println("you can do something");
    }

    public static void main(String[] args) {
        EnumSingleton1.INSTANCE.doSomething();
        EnumSingleton1.INSTANCE.testname="111";
        EnumSingleton1.INSTANCE.printTest();

    }

}
